title: Methyl 2-(2,2-dimethyl-3a,6a-di-hydro-furo[3,2-d][1,3]dioxol-5-yl)-4-oxo-4H-chromene-3-carboxyl-ate.
abstract: In the title mol-ecule, C18H16O7, the dioxolane ring adopts an envelope conformation with the dimethyl-substituted C atom as the flap. The furan ring is almost coplanar with the pyran ring, with a dihedral angle of 1.04 (10)° between the planes, and it makes a dihedral angle of 67.97 (11)° with the mean plane of the dioxolane ring. The latter makes a dihedral angle of 67.15 (10)° with the pyran ring. The O atom attached to the pyran ring deviates by -0.009 (1) Å. The crystal packing features C-H⋯O hydrogen bonds, forming a three-dimensional structure. The meth-oxy-carbonyl atoms are disordered over two positions, with a refined occupancy ratio of 0.508 (18):0.492 (18).
authors.affiliation: Centre of Advanced Study in Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai 600 025, India.
authors.forename: Zeenat
authors.initials: Z
authors.lastname: Fatima
authors.forename: Thothadri
authors.initials: T
authors.lastname: Srinivasan
authors.forename: Jonnalagadda Naga Siva
authors.initials: JN
authors.lastname: Rao
authors.forename: Raghavachary
authors.initials: R
authors.lastname: Raghunathan
authors.forename: Devadasan
authors.initials: D
authors.lastname: Velmurugan